The present invention relates to network switching, and more particularly to Layer 2 through Layer 7 switching.
This invention relates to uses for network switches, and more particularly to filters and policies for managing and controlling user applications using network switches.
The OSI (Open System Interconnection) Model is an ISO standard for worldwide communications that defines a networking framework for implementing protocols in seven layers. Control is passed from one layer to the next, starting at the applications layer in one station, proceeding to the physical layer and back up the hierarchy.
The layers are defined as:
Applications Layer 7 provides interface to end-user processes and standardized services to applications.
Presentation Layer 6 specifies architecture-independent data transfer format, encodes and decodes data, encrypts and decrypts data, compresses data.
Session Layer 5 manages user sessions and reports upper-layer errors.
Transport Layer 4 manages network layer connections and provides reliable packet delivery mechanism.
Network Layer 3 addresses and routes packets.
Data Link Layer 2 frames packets and controls physical layer data flow.
Physical Layer 1 interfaces between network medium and network devices. Also defines electrical and mechanical characteristics.